• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.4C
• /
• pp.533-540
• /
• 2004

This paper proposes a new multispectral image data compression algorithm that can efficiently reduce spatial and spectral redundancies by applying classified prediction, a Karhunen-Loeve transform (KLT), and the three-dimensional set partitioning in hierarchical trees (3-D SPIHT) algorithm in the wavelet transform (WT) domain. The classification is performed in the WT domain to exploit the interband classified dependency, while the resulting class information is used for the interband prediction. The residual image data on the prediction errors between the original image data and the predicted image data is decorrelated by a KLT. Finally, the 3-D SPIHT algorithm is used to encode the transformed coefficients listed in a descending order spatially and spectrally as a result of the WT and KLT. Simulation results showed that the reconstructed images after using the proposed algorithm exhibited a better quality and higher compression ratio than those using conventional algorithms.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.2
• /
• pp.27-38
• /
• 2003

The characteristics and prediction model of the shear strength of unsaturated residual granite soils were studied in this paper. In order to investigate the influence of the net normal stress on the shear strength, unsaturated triaxial tests and SWCC tests were carried out by varying the net normal stress. Experimental data for unsaturated shear strength tests were compared with predicted shear strength envelopes obtained from existing prediction models. It was shown that the soil-water characteristic curve and the shear strength of the unsaturated soil varied with the change of the net normal stress. Therefore, to achieve a truly descriptive shear strength envelope for unsaturated soils, the effect of the normal stress on the contribution of matric suction to the shear strength has to be taken into consideration. In this paper, a modified prediction model f3r the unsaturated shear strength was proposed.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.14 no.1
• /
• pp.7-15
• /
• 1994

The two-dimensional elastoplastic analysis was peformed to reveal a detail residual stress distribution of ceramic/metal joint specimen using finite element method and X-ray method. The highest tensile residual stress, ${\sigma}_x$ perpendicular to the interface appeared at the edge of the ceramic near the interface. In the vicinity of the interface, the high stress concentration occurs and residual stress distributes three-dimensionally. Therefore, the measured stress distribution differed remarkably from the result of the two-dimensional finite-element analysis. Especially at the center of the specimen near the interface, the residual stress, ox obtained from the finite element analysis was compressive, whereas X-ray measurement yielded tensile ${\sigma}_x$. Therefore, it is also attempted to investigate the finite element model for the prediction of residual stress ${\sigma}_x$ distributed nearly the interface of joint.

• Journal of the Korea Concrete Institute
• /
• v.17 no.6 s.90
• /
• pp.893-902
• /
• 2005

Reasonable prediction of residual capacity of fire-damaged reinforced columns is important for both the safety measurement and the rehabilitation of the reinforced concrete structures suffered from exposure to extensive fire. In order to predict the residual behavior of fire-damaged reinforced concrete columns, its predictive model must be able to take into account the amount of heat transferred into the column, the level of deterioration of constituent materials and various column geometries. The numerical model presented in this research includes all these factors. The model has been shown to reasonably predict the residual behavior of fire-damaged columns. Parametric studies were performed using this model for the effects of cover thickness, exposure time to fire and column geometries on the residual behavior of reinforced concrete columns. It was found that serious damage on the residual capacity of column resulted from a longer exposure time to fire but only marginal differences from other factors.

• Proceedings of the KSME Conference
• /
• 2005.11a
• /
• pp.144.1-144.1
• /
• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.1309-1310
• /
• 2011

• Journal of Biosystems Engineering
• /
• v.40 no.1
• /
• pp.47-60
• /
• 2015

Purpose: The purpose of this study was to non-destructively and quickly predict the capsaicinoid content of domestic red pepper powders from various areas of Korea using a pungency measurement system in combination with visible and near-infrared (VNIR) spectroscopic techniques. Methods: The reflectance spectra of 149 red pepper powder samples from 14 areas of Korea were obtained in the wavelength range of 450-950 nm and partial least squares regression (PLSR) models for the prediction of capsaicinoid content were developed using area models. Results: The determination coefficient of validation (RV2), standard error of prediction (SEP), and residual prediction deviation (RPD) for the capsaicinoid content prediction model for the Namyoungyang area were 0.985, ${\pm}2.17mg/100g$, and 7.94, respectively. Conclusions: These results show the possibility of VNIR spectroscopy combined with PLSR models in the non-destructive and facile prediction of capsaicinoid content of red pepper powders from Korea.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.9
• /
• pp.1215-1221
• /
• 2016

The prediction of carcass composition in Hanwoo steers is very important for value-based marketing, and the improvement of prediction accuracy and precision can be achieved through the analyses of independent variables using a prediction equation with a sufficient dataset. The present study was conducted to develop a prediction equation for Hanwoo carcass composition for which data was collected from 7,907 Hanwoo steers raised at a private farm in Gangwon Province, South Korea, and slaughtered in the period between January 2009 and September 2014. Carcass traits such as carcass weight (CWT), back fat thickness (BFT), eye-muscle area (EMA), and marbling score (MAR) were used as independent variables for the development of a prediction equation for carcass composition, such as retail cut weight and percentage (RC, and %RC, respectively), trimmed fat weight and percentage (FAT, and %FAT, respectively), and separated bone weight and percentage (BONE, and %BONE), and its feasibility for practical use was evaluated using the estimated retail yield percentage (ELP) currently used in Korea. The equations were functions of all the variables, and the significance was estimated via stepwise regression analyses. Further, the model equations were verified by means of the residual standard deviation and the coefficient of determination ($R^2$) between the predicted and observed values. As the results of stepwise analyses, CWT was the most important single variable in the equation for RC and FAT, and BFT was the most important variable for the equation of %RC and %FAT. The precision and accuracy of three variable equation consisting CWT, BFT, and EMA were very similar to those of four variable equation that included all for independent variables (CWT, BFT, EMA, and MAR) in RC and FAT, while the three variable equations provided a more accurate prediction for %RC. Consequently, the three-variable equation might be more appropriate for practical use than the four-variable equation based on its easy and cost-effective measurement. However, a relatively high average difference for the ELP in absolute value implies a revision of the official equation may be required, although the current official equation for predicting RC with three variables is still valid.

• Journal of Welding and Joining
• /
• v.25 no.1
• /
• pp.42-48
• /
• 2007

For high performance and structural stability, application of high strength steel has continuously increased. However, the change of the base metal gives rise to problems with the accuracy management of the welded structure. It is attributed to the martensite phase transformation of the high strength low alloy steel weldment. The purpose of this study is to establish the predictive equation of transverse shrinkage and residual stress for the HY-100 weldment. In order to do it, high speed quenching dilatometer tests were performed to define a coefficient of thermal expansion(CTE) at the heating and cooling stage of HY-100 with various cooling rates. Uncoupled thermal-mechanical finite element(FE) models with CTE were proposed to evaluate the effect of the martensite phase transformation on transverse shrinkage and residual stresses at the weldment. FEA results were verified by comparing with experimental results. Based on the results of extensive FEA and experiments, the predictive equation of transverse shrinkage and longitudinal shrinkage force at the HY-100 weldment were formulated as the function of welding heat input/in-plane rigidity and welding heat input respectively.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.7
• /
• pp.1426-1437
• /
• 2002

Using the Lagrangian explicit time-integration finite element code NET3D which can treat three-dimensional high-velocity impact problems, oblique penetration processes of long rod projectile with yaw against thin plate are simulated. Through the comparison of simulation result with experimental result and other code's computational result, the adaptability and accuracy of NET3D is evaluated under the complex situation in which yaw angle and oblique angle exist simultaneously. Main research contents to be handled in this paper include the followings. First, the accuracy and efficiency estimation of NET3D code result obtained from the oblique penetration simulations of long rod projectile with yaw against thin plate. Second, the effect of increasing impact velocity. Third, the effect of initial yaw for the spaced-plate target. Residual velocities, residual lengths, angular velocities, and final deformed configurations obtained from the NET3D computations are compared with the experimental results and other code's computational results such as Eulerian code MESA and Lagrangian code EPIC. As a result of comparisons, it has been found that NET3D code is superior to EPIC code and MESA code in the prediction capability of residual velocity and residual length of penetrator. The key features obtained from the experiment can be successfully reproduced through NET3D simulations. Throughout the study, the applicability and accuracy of NET3D as a metallic armor system design tool is verified.